Merge branch 'lua_effect_expire' into 'master'

Add notes about lua active effects technicality

See merge request OpenMW/openmw!3516

files/lua_api/openmw/core.lua

@@ -675,11 +675,13 @@
 
 ---
 -- @type ActiveEffect
+-- Magic effect that is currently active on an actor.
+-- Note that when this effect expires or is removed, it will remain temporarily. Magnitude will be set to 0 for effects that expire.
 -- @field #string affectedSkill Optional skill ID
 -- @field #string affectedAttribute Optional attribute ID
 -- @field #string id Effect id string
 -- @field #string name Localized name of the effect
--- @field #number magnitude
+-- @field #number magnitude current magnitude of the effect. Will be set to 0 when effect is removed or expires.
 -- @field #number magnitudeBase
 -- @field #number magnitudeModifier